Ultraviolet radiation has been known as a cellular mutagen for over 100 years. UV sterilizers utilize UV light wavelengths in the range of about 210 nm (nanometers) to about 290 nm. Gases that emit light in the UV wavelength range of about 10 nm to 400 nm are mercury vapor, hydrogen, nitrogen, oxygen, fluorine, bromine, iodine, helium, neon, argon, krypton, xenon, radon, mixtures of gases also produce light in the near UV range. Some gases include, but are not limited to, xenon mixed with halides and hydrogen mixed with ammonia. Since mercury vapor emits UV at a wavelength of 254 nm, which is near the center of the germicidal range, mercury vapor is widely used as the excitable gas in UV sterilizers.
There are many UV sterilizers on the market today. There are many advantages for using plasma-shells over traditional tube-type lamps. The plasma-shells are more rugged than traditional quartz lamps. The plasma-shells have a greater overall surface area, thereby increasing the amount of UV light that can be used to sterilize liquids, gases, and/or solids. UV light is used in medical applications. UV light is used in to photo cure materials such as polymers and dental ceramics. The shell material of a plasma-shell may be selected to provide increased UV emission. The plasma-shell produces less heat than traditional quartz lamps with a lifespan. Quartz lamps typically use dangerous mercury vapor to generate UV emission. These lamps need to be managed according to special disposal laws and regulations. Rare gases used alone or in combination with rare gases and/or other gases discussed herein such as neon, argon, xenon, krypton, and helium may be used in plasma-shells and do not require any special disposal procedures.